Material for shoe stiffeners



Patented @ct. l3, 1%42 assent 2,298,274 I MATERIAL FOR SHOE STHFENERSHugo Boeddinghaus, Newburg N. Y., assignor to American Felt Company, NewYork, N. Y a corporation of Massachusetts No Drawing. Application August3, i940, Serial No. 351,237

4 Claims.

This application is a continuation-impart of my co-pending applicationSerial No. 328,768, filed April 9, 1940, for Felt-like fabrics andmethod of producing the same, which in turn is a continuation-in-part ofmy application Serial No. 211,926, filed June 4, 1938.

The invention of this present application reiates to material for shoestifieners, and has for its principal objects to provide an improvedshoe stiffener capable of being made in a simpler manher than prior shoestiifeners, easy to ship and handle, and easy to soften and bend intothe appropriate curved shape for application to the shoe.

Other objects of invention and features of advantage and utility will beapparent from this specification wherein the invention is explained byway of example.

In a preferred example of th invention, material is prepared in a mannernow to be described. A thorough mixture of from 30%, or preferably morethan 30%, up to approximately 50% synthetic thermoplastic fibers and theremainder of cotton fibers (preferably about 40% synthetic fibers and60% cotton fibers) is prepared by subjecting both kinds of fiberstogether to a picking operation, to a blowing operation (usuallyrepeated a number of times), and to a carding operation (preferably atleast twice). The effect of these operations is to produce a thin cardedweb in which the thermoplastic fibers and the nonthermoplastic fibersare very uniiormly distributed throughout the web. A plurallty of thesewebs are then superposed to provide a batt of material weighing, forexample, 35 ounces per square yard, the exact weight depending upon therequirements of the trade.

- The batt is then subjected to ahot-pressing operation to bond thethermoplastic fibers. For this urpos the apparatus disclosed in mycopending application for Bonding sheet material, filed July 30, 1940,Serial No. 348,371, may be employed. In this hot-pressing operation, thebatt of material is subjected to a pressure of approximately 700 poundsper square inch between press plates that are heated to approximately300 F. The material is protected from adhesion to the press plates bysuitable non-thermoplastic textile aprons during the pressing.

The resulting product is a thin sheet of approximately .55 to .65 inchthickness of stifiness and bendability comparable to shoe stifienerscustomarily used. Thi sheet material can be cut to the usual shape of ashoe stiflener, for ex- 65 QII ample, to the shape of a box toestiffener, and its edges skived in the customary manner.

The shoe stiiiener produced bythis procedure thus comprises a sheet inwhich the requisite.

stifiness and strength is secured by means of the fibrous material ofwhich the sheet is composed, so that no filling or weighting material,such as wax, rosin or the like, need be employed.

lhe. stiiieners, produced as described, canbe shipped in a dry state tothe shoe factory and can be stored for as long as desired without dangerof deterioration. To prepare the stifieners for use they can be softenedeither by application ofheat or by application of a suitable volatilesolvent, and bent to the desired shape on the last. In using a solventfor the purpose of softening the stifieners, there should be appliedonly sufficient solvent action to soften the material and not todisintegrate the thermoplastic fibers of the material.

As the thermoplastic fiber, there may b employed a considerable range offibrous material, the requirements being in general that thesethermoplastic fibers shall be sufficiently long, strong and pliable towithstand the carding operation and be capable of softening sumcientlyto bond with one another at temperatures sufiiciently low not to harmthe cotton fibers. A, preferred thermoplastic fiber for this purpose hasbeen found to be a plasticized acetate rayon, available under the tradename of Tenite. Other suitable fibers are:

1. Vinylite, also known under the trade name of Vinyon, a conjointpolymer of avinyl halide with a vinyl ester of a lower molecularaliphatic acid as vinyl acetate, referred to at times as vinyl resinfibers.

2. Methyl methacrylate resins such as are available under the trade nameof Lucite.

3. Nylon, a polyamide produced by the reaction between a primary or a.secondary diamine and either a dicarboxylic acid or an amide-formingderivative of a dibasic carbolic acid.

I claim:

1-. A shoe stiffener in the form of a sheet consisting of a cardedmixture of from more than 30 per cent to approximately 50 per cent ofthermoplastic fibers and the remainder substantially all cotton fibers,said mixture being bonded and compacted to a stifi condition by hotpressure and being capable of being softened by th action of heat orsolvent.

2. A shoe stifiener in the form of a sheet consisting of a cardedmixture of approximately '40 per cent of thermoplastic fibers andapproximately 60 per cent or cotton fibers, said mixture being bondedand compacted to astifl condition by hot pressure and being capable ofbeing softened by'the action or heat or solvent.v

3. A shoe stiflener in the form 01 a sheet consisting of a cardedmixture 01' from more than 30 per cent to approximately 50 per cent ofthermoplastic fibers and the remainder substantially all cotton fibers,said mixture being bonded and compacted to a stiff condition by hotpressure, being capable of being softened by the action of heat orsolvent and weighing approximately 35 ounces per square yard.

10 in thickness.

4. A shoe stiflener in the form or a sheet consisting of a cardedmixture of from more than 30 per cent to approximately 50 per cent ofthermoplastic fibers and the remainder substantially all cotton fibers,said mixture being bonded .and compacted to a still! condition by hotpressure, and being capable or being softened by the action oi heat orsolvent and said sheet being approximately 0.55 inch to approximately0.65 inch rroao BOEDDINGHAUS.

